The present invention relates to an image forming apparatus for forming image information corresponding to its original image on recording sheets, more specifically to an image forming apparatus for allowing copy fee or printing fee at the store installing the apparatus therein to be automatically calculated and displayed.
Recently, the number of copy or printing shops for serving copying or printing by using electrophotographic copy machines or mimeographic printing machines has been increased in convenience stores and stationary stores.
The image forming apparatus corresponding to these purposes of the prior art are provided with a mechanical key-counter for enabling the use of the apparatus by attaching therein. Once copying or printing is completed, the copy or print fee is calculated based on the data of the number of printed sheets and the unit price per sheet for the size of recording sheets.
The fare adjustment may be easy when the printed sheet size is limited to one or two. However, in case that a plurality of different sizes of recording sheets has been used, the calculation of the printing charge may be a bothering job, and may result in the problem of frequent calculation errors.